Measurement system and measurement method

Abstract

The measurement system comprises a holder for holding a dielectric film formed on at least a semiconductive substrate and sandwiched between the substrate and a conductive film, voltage application terminals for applying voltage between the substrate and the conductive film, variable voltage source for supplying the voltage to the voltage application terminals, a light source for irradiating the dielectric film with light including wavelength of an infrared region and transmitting the light through the dielectric film, light absorbance detector receiving the light transmitted through the dielectric film, for detecting absorbance of an absorbed light component in an absorption wavelength region intrinsic to the dielectric film, and a potential difference measurement unit for measuring a potential difference between the substrate and the conductive film of the dielectric film on the basis of change in absorbance of the light component when the voltage is changed by the variable voltage source.

We claim: 
     
       1. A measurement system comprising: holding means for holding a dielectric film formed on at least a semiconductive substrate and sandwiched between the substrate and a conductive film;   voltage application means for applying voltage between the substrate and the conductive film;   variable voltage source for supplying the voltage to the voltage application means;   light radiation means for irradiating the dielectric film with light including wavelength of an infrared region and transmitting the light through the dielectric film;   light absorbance detection means receiving the light transmitted through the dielectric film, for detecting absorbance of an absorbed light component in an absorption wavelength region intrinsic to the dielectric film; and   potential difference measurement means for measuring a potential difference between the substrate and the conductive film of the dielectric film on the basis of change in absorbance of the light component when the voltage is changed by the variable voltage source.   
     
     
       2. The measurement system according to claim 1, wherein the holding means holds a dielectric film containing one element selected from the group consisting of silicon dioxide, silicon nitride, silicon carbide, aluminum oxide, zirconium oxide, cupric oxide and tungsten oxide. 
     
     
       3. The measurement system according to claim 1, wherein the conductive film has a transmittance to the light within absorption wavelength region intrinsic to the dielectric film which is 1/20 or more of transmittance to the light including the absorption wavelength region. 
     
     
       4. A measurement method comprising the steps of: applying voltage to a dielectric film sandwiched between at least a semiconductive substrate and a conductive film;   irradiating the dielectric film with light including wavelength of an infrared region and transmitting the light therethrough;   receiving the light transmitted through the dielectric film and measuring absorbance of the light; and   measuring a potential difference between the substrate and the conductive film of the dielectric film on the basis of change in absorbance of the light within an absorption wavelength range intrinsic to the dielectric film when the voltage is changed.   
     
     
       5. The measurement method according to claim 4, wherein the step for applying voltage includes a step of applying the voltage to a dielectric film containing one element selected from the group consisting of silicon dioxide, silicon nitride, silicon carbide, aluminum oxide, zirconium oxide, cupric oxide and tungsten oxide. 
     
     
       6. The measurement method according to claim 4, wherein the step of applying the voltage employs a conductive film having a transmittance to the light within absorption wavelength region intrinsic to the dielectric film which is 1/20 or more of transmittance to the light including the absorption wavelength range. 
     
     
       7. A measurement system comprising: plasma treatment means for applying a predetermined plasma treatment to a dielectric film on a substrate by use of plasma, the plasma treatment means having an electrode serving as a susceptor on which the substrate is to be mounted;   light radiation means for irradiating the dielectric film with light including wavelength of an infrared region and transmitting the light through the dielectric film;   light absorbance detection means for detecting absorbance of light within an absorption wavelength region intrinsic to the dielectric film, among the light absorbed by the dielectric film; and   potential difference measurement means for measuring a potential difference of the dielectric film charged with the plasma, on the basis of a difference in the light absorbance between before plasma treatment and during the plasma treatment.   
     
     
       8. The measurement system according to claim 7, wherein the plasma treatment means has an RF power source for plasma generation, and the RF power source supplies a pulse-form RF power having a pulse interval controlled on the basis of measurement results by the potential difference measurement means. 
     
     
       9. The measurement system according to claim 7, wherein the plasma treatment means treats a dielectric film containing one element selected from the group consisting of silicon dioxide, silicon nitride, silicon carbide, aluminum oxide, zirconium oxide, cupric oxide and tungsten oxide. 
     
     
       10. The measurement system according to claim 9, wherein the dielectric film has a transmittance to the light within an absorption wavelength region intrinsic to the dielectric film which is 1/20 or more of transmittance to the light including the absorption wavelength region. 
     
     
       11. A measurement method comprising the steps of: irradiating a dielectric film with light including wavelength of an infrared region; and   measuring a potential difference of the dielectric film charged with plasma on the basis of change in absorbance of the light within absorption wavelength range intrinsic to the dielectric film, among the light absorbed by the dielectric film.   
     
     
       12. The measurement method according to claim 11, wherein the step of irradiating the dielectric film with light employs a dielectric film containing one element selected from the group consisting of silicon dioxide, silicon nitride, silicon carbide, aluminum oxide, zirconium oxide, cupric oxide and tungsten oxide. 
     
     
       13. A measurement system comprising: a current detection electrode exposed in an interior of a plasma treatment chamber for performing plasma treatment and electrically isolated from the plasma treatment chamber, the plasma electrode being applied with a negative voltage;   an insulation member electrically isolating the current detection electrode from the plasma treatment chamber and arranged around the current detection electrode to prevent the current detection electrode from being exposed to a material present in the plasma treatment chamber; and   contaminant measuring means for measuring an amount of contaminant present in the plasma treatment chamber on the basis of current detected by the current detection electrode.   
     
     
       14. The measurement system according to claim 13, wherein the insulation member has a transmission hole communicating between an interior portion and an exterior portion of the plasma treatment chamber, the current detection electrode is inserted from the exterior portion through the transmission hole in such a manner that a distal end of the current detection electrode is allowed to remain in the transmission hole. 
     
     
       15. The measurement system according to claim 13, wherein a diameter of the transmission hole is equal to or longer than a debye length of a reaction species generating plasma, and a distance between the distal end of the current detection electrode and an inner wall of the plasma treatment chamber is equal to or more than a mean free path of the reaction species. 
     
     
       16. A measurement method comprising the steps of: preparing a current detection electrode in an interior portion of a plasma treatment chamber for performing plasma treatment in such a manner that an distal end of the electrode is exposed in a transmission hole in an insulation member, the current detection electrode being charged with a negative voltage to the plasma treatment chamber; and   measuring a contamination amount in the plasma treatment chamber on the basis of current detected by the detection electrode while deposition of a material present in the plasma treatment chamber on the current detection electrode is being prevented by inserting the current detection electrode into the transmission hole formed of the insulation member.   
     
     
       17. A measurement system comprising: light radiation means for irradiating a treatment substrate with light including wavelength of an infrared region;   temperature/film-thickness measurement means for measuring temperature and film-thickness of the treatment substrate simultaneously, the temperature being measured on the basis of change in wavenumber of absorption peak within an absorption wavelength region intrinsic to the treatment substrate, among the light absorbed by the treatment substrate and previously-prepared data regarding temperature dependency of an absorption spectrum with respect to the treatment substrate; and the film-thickness being measured on the basis of change in absorbance of light within the absorption wavelength region intrinsic to the treatment substrate and previously-prepared data regarding film-thickness dependency of absorption spectrum with respect to the treatment substrate.   
     
     
       18. The measurement system according to claim 17, wherein the light radiation means irradiates anyone of the treatment substrate containing silicon, the treatment substrate containing silicon and oxygen, and the treatment substrate containing silicon and nitrogen with the light. 
     
     
       19. A measurement system comprising: light radiation means for irradiating a treatment substrate with light including at least two wavelengths of an infrared region; and   a temperature measurement means for measuring the treatment substrate on the basis of change in absorbance of light containing at least two wavelengths in an absorption wavelength region intrinsic to the treatment substrate, among the light absorbed in the treatment substrate, and on the basis of previously prepared data regarding temperature dependency of absorption spectra of at least two light wavelengths with respect to the treatment substrate.   
     
     
       20. The measurement system according to claim 19, further comprising previously-prepared data regarding film-thickness dependency of absorption spectra of at least two light wavelengths absorbed by the treatment substrate and further comprising film-thickness measurement means for measuring film-thickness of the treatment substrate. 
     
     
       21. The measurement system according to claim 20, wherein the light including at least two wavelengths of an infrared region includes a light having a wavenumber exceeding 1080 cm -1  and a light having a wavenumber of 1080 cm -1  or less, and the treatment substrate is formed of a thin film containing silicon and oxygen. 
     
     
       22. The measurement system according to claim 20, wherein the light including at least two wavelengths in an infrared region includes a wavenumber exceeding 1100 cm -1  and a wavenumber of 1080 cm -1 , and the treatment substrate is formed of a thin film containing silicon and oxygen.